|
|||||
|
|
Synthesis of rare earth phosphates in molten LiCl-KCl eutectic: Application to preliminary treatment of chlorinated waste streams containing fission products |
|
| Authors: | Damien Hudry Isabelle Bardez Catherine Bessada Florence Bart Philippe Deniard |
| Affiliation: | a CEA Marcoule DTCD/SECM/LDMC, BP 17171, 30207 Bagnols sur Cèze cedex, France b Conditions Extrêmes et Matériaux Hautes Températures et Irradiations, CEMHTI-CNRS, 45071 Orléans cedex 2, France c Université d’Orléans, Faculté des Sciences, BP 6749, 45067 Orléans cedex 2, France d Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes cedex 3, France |
| Abstract: | The precipitation of rare earth phosphates (RE = La, Ce, Pr, Nd, and Lu), from RECl3 was investigated in molten LiCl-KCl eutectic at 500 °C in air. Ammonium dihydrogenphosphate (NH4H2PO4) was used as the phosphorus precursor. X-ray diffraction analysis indicated the formation of compounds with monazite (La, Ce, Pr, and Nd) or xenotime (Lu) structures. 31P NMR spectroscopy measurements confirmed that lanthanum formed pure monazite, which indicates a LaCl3 → LaPO4 conversion factor near 100%. These results demonstrate that the stoichiometric addition of NH4H2PO4 is sufficient to obtain quantitative precipitation at 500 °C of anhydrous rare earth phosphates in molten LiCl-KCl. The use of this type of precursor, which has the advantage of not modifying the chemical composition of the medium after recovery of the rare earth phosphates, could be considered during the first step of purification of chlorinated baths containing fission products arising from spent fuel reprocessing by a pyrochemical process. |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ | |